#include <stdio.h>
#include <unistd.h>


/*  执行命令：./helloworld weidongshan
 *  aregc  = 2
 *  aregc[0] = ./hello
 *  aregc[1] = weidongshan
 */

int main(int argc , char **argv){
   if(argc >= 2){
       printf("Hello,%s\n",argv[1]);
   }
   else{
       printf("Hello_word\n");
   }
   return 0;
}